DMAENGINE: ste_dma40: support older silicon

This makes sure the DMA40 driver will also work on the oldest
silicon revisions that have the on-chip memory on another location
in the DB8500 and also requires explicit suspend before starting
or resuming a logical channel.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
[added parenthesis to the definition of U8500_DMA_LCPA_BASE_ED]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 28 insertions, 4 deletions

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 1d21fbd419d1..21a759731ef1 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -218,6 +218,7 @@ struct d40_chan {
  * the same physical register.
  * @dev: The device structure.
  * @virtbase: The virtual base address of the DMA's register.
+ * @rev: silicon revision detected.
  * @clk: Pointer to the DMA clock structure.
  * @phy_start: Physical memory start of the DMA registers.
  * @phy_size: Size of the DMA register map.
@@ -250,6 +251,7 @@ struct d40_base {
         spinlock_t                       execmd_lock;
         struct device                    *dev;
         void __iomem                     *virtbase;
+        u8                                rev:4;
         struct clk                       *clk;
         phys_addr_t                       phy_start;
         resource_size_t                   phy_size;
@@ -757,6 +759,17 @@ static dma_cookie_t d40_tx_submit(struct dma_async_tx_descriptor *tx)
 
 static int d40_start(struct d40_chan *d40c)
 {
+        if (d40c->base->rev == 0) {
+                int err;
+
+                if (d40c->log_num != D40_PHY_CHAN) {
+                        err = d40_channel_execute_command(d40c,
+                                                          D40_DMA_SUSPEND_REQ);
+                        if (err)
+                                return err;
+                }
+        }
+
         if (d40c->log_num != D40_PHY_CHAN)
                 d40_config_set_event(d40c, true);
 
@@ -1426,6 +1439,13 @@ static int d40_resume(struct dma_chan *chan)
 
         spin_lock_irqsave(&d40c->lock, flags);
 
+        if (d40c->base->rev == 0)
+                if (d40c->log_num != D40_PHY_CHAN) {
+                        res = d40_channel_execute_command(d40c,
+                                                          D40_DMA_SUSPEND_REQ);
+                        goto no_suspend;
+                }
+
         /* If bytes left to transfer or linked tx resume job */
         if (d40_residue(d40c) || d40_tx_is_linked(d40c)) {
                 if (d40c->log_num != D40_PHY_CHAN)
@@ -1433,6 +1453,7 @@ static int d40_resume(struct dma_chan *chan)
                 res = d40_channel_execute_command(d40c, D40_DMA_RUN);
         }
 
+no_suspend:
         spin_unlock_irqrestore(&d40c->lock, flags);
         return res;
 }
@@ -2286,6 +2307,7 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
         int num_log_chans = 0;
         int num_phy_chans;
         int i;
+        u32 val;
 
         clk = clk_get(&pdev->dev, NULL);
 
@@ -2324,12 +2346,13 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
                 }
         }
 
-        i = readl(virtbase + D40_DREG_PERIPHID2);
+        /* Get silicon revision */
+        val = readl(virtbase + D40_DREG_PERIPHID2);
 
-        if ((i & 0xf) != D40_PERIPHID2_DESIGNER) {
+        if ((val & 0xf) != D40_PERIPHID2_DESIGNER) {
                 dev_err(&pdev->dev,
                         "[%s] Unknown designer! Got %x wanted %x\n",
-                        __func__, i & 0xf, D40_PERIPHID2_DESIGNER);
+                        __func__, val & 0xf, D40_PERIPHID2_DESIGNER);
                 goto failure;
         }
 
@@ -2337,7 +2360,7 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
         num_phy_chans = 4 * (readl(virtbase + D40_DREG_ICFG) & 0x7) + 4;
 
         dev_info(&pdev->dev, "hardware revision: %d @ 0x%x\n",
-                 (i >> 4) & 0xf, res->start);
+                 (val >> 4) & 0xf, res->start);
 
         plat_data = pdev->dev.platform_data;
 
@@ -2359,6 +2382,7 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
                 goto failure;
         }
 
+        base->rev = (val >> 4) & 0xf;
         base->clk = clk;
         base->num_phy_chans = num_phy_chans;
         base->num_log_chans = num_log_chans;